The purpose of one part of this Core is to obtain, preserve, examine, collate, and disseminate postmortem human brain tissue after minimal postmortem delay. Toward this goal we have assembled a staff composed of the Core director, a board certified neuropathologist, histotechnologist, and two 24-hour, on-call pathology technicians. This Core will be responsible for assuring that all brains referred to as AD meet the standard neuropathological criteria. Many of the Core functions, pertaining to the autopsy and histopathological examination, required will be at no cost to our Program as they are part of the routine pathology examination at the McClellan VA Hospital. The McClellan Hospital is new 1,500 bed hospital with a 1,000 bed psychiatric chronic care facility. The Geriatrics Research and Education Core at this facility currently has 400 outpatients. We have been assured of the cooperation of the officials at these institutions, by word, letter, and by our previous collaborations. Another function of the Core, which will more directly involve the director and postdoctoral fellow, will be to provide immunohistochemistry at the light and electronmicroscopic levels, Western immunoblot analysis, and Northern and in situ hybridization services on human tissue samples and cultured cells, upon request. This Core will provide tissues and services that will enhance and facilitate achievement of the aims of the Projects and Cores in this Program, dedicated to providing information about relationships that may form a link between the pathological features of glia, neurons, and extracellular mineral deposits in an age-related disorder, AD.